This may sound dumb but I just want to make sure I have it right.

1) Domain Names must have no less than 2 Name Servers, both of which can be on the same machine, but with each having a different ID (i.e. - ns1.AserverA.com and ns2.AserverA.com) and with each having a different IP address.

2) If more than 2 NSs are listed (i.e. - ns1.XfooX.com and ns1.YbarY.com - 2 physically different machines):
a) Resolving the DN takes place in listed order of NSs, and
b) The Domain's data must exist on each and every one of the machines, and
c) Attempts to resolve the DN continues on down the list of NSs until either successfully resolved at an NS or until the list of NSs is exhausted without success, and
d) If the 2 original NSs are removed/deleted, the others move up in rank.

That's how I interpreted the Regs but, ya know, sometimes some of us on the back side of the longevity hill have a problem understanding that a=c in the equation a=b=c :rolleyes:

Thanks, in advance, for the help.

--Yizit

1) Yes. But the point of having different nameservers is redundancy, so if one goes down your domain doesn't stop resolving. You can actually have both nameservers have the same IP address. Again, same deal: no redundancy.

2a) No, it happens randomly. There is no "preferred" nameserver.
2b) Yes. That would probably be a good idea.
2c) I'm not sure.
2d) As far as I know, there is no concept of "rank" in DNS nameservers.

1) so many domains runs on 1 nameserver i.e egypt.com, technically its possible but worse case ever.
2a) answered
b) yes and master dns sually update slaves every X time
c) yes it will go into all nameservers till it find one alive
d) yes any listed NS will reply

Thanks aebrahim and Bashar. I appreciate the clarifications. I can see I had some misconceptions. However, there are a couple of things that are still not clear to me.

1) Although you both indicate that resolving the location of a Domain happens randomly, Bashar refers to a "master dns updating slaves". How is it determined as to which is the "master" dns and which ones are the "slaves"?

2) Can I have one DNS indicate that the Domain resides at 010.020.030.040 and another DNS indicate that the Domain resides at 050.060.070.080 and replicate the Domain's data exactly at each location?

If so, what would happen under the following scenario:
DNS ns1.XfooX.com indicates that the Domain's data is at 010.020.030.040 but that machine is down. Would a "Domain Not Found" error occur or would it continue on to the next DNS which indicates that the Domain's data is at 050.060.070.080?

Hope I'm not confusing everyone.

--Yizit

1) its how you setup your nameservers which master and which slave

2) cant be, seems one is behinde, check it from www.dnsreport.com

no it wont , its just gonna pont once here and once there depending on the lookup

This thread has been pretty much answered just want to add one point to 2c.

The resolving name server will go through the list (round robined in nature) until it get's answer.
It will go through the list of name servers until it runs out of name server OR until the resolving name server just times out. The timeout can usually be set.

So you can have as many as 13 name servers (UDP limitation which is why there are only 13 root name server). But not all 13 will be queried if the resolving name servers just decides that it's done.